The present invention relates to an improved slide valve for the outlet of a metallurgical vessel and of the type including a stationary plate having a flow-through opening and fixedly positioned beneath an outlet in a metallurgical vessel and a slide plate mounted for sliding movement with respect to the stationary plate and having plural flow-through openings.
More particularly, the present invention is directed to such an improved slide valve whereby it is possible to inject gas, liquid and/or solid material into at least one flow-through opening in the slide valve and/or into the metallurgical vessel.
West German DT-OS No. 2,404,881 discloses a slide valve including a rotary slide plate having therethrough two flow-through openings. Outlet nozzles are attached to the slide plate adjacent each flow-through opening therein. Each outlet nozzle includes a refractory shell with a metal coupling sleeve therearound. The coupling sleeve has plug-type connections to enable coupling of the outlet nozzle to the metallic frame of the rotary slide plate. In this manner, it is possible to easily replace worn or corroded refractory shells. These readily replaceable outlet nozzles are also advantageous for maintaining the rate of outflow of a liquid melt from the metallurgical vessel constant without having to regulate the flow by means of adjusting movement of the slide plate. This is achieved by selectively replacing the outlet nozzles with new outflow nozzles having progressively increasing diameters as the level of liquid melt within the vessel decreases.
Additionally, West German DT-AS No. 1,935,401 discloses a slide valve including a slide plate having therein gas tubes or inlets for the injection of a gas to retard or prevent solidification of melt at the inlet of the slide valve or to produce a flushing operation of the melt.